Sending transactions in Blockchain / Solidity - Step-by-Step Execution

Concept Flow - Sending transactions

Create transaction data

↓

Sign transaction with private key

↓

Broadcast transaction to network

↓

Network validates transaction

↓

Transaction added to block

↓

Transaction confirmed

This flow shows how a transaction is created, signed, sent to the network, validated, and finally confirmed.

Execution Sample

Blockchain / Solidity

tx = {"to": "0xABC123", "value": 10}
signed_tx = sign(tx, private_key)
broadcast(signed_tx)
// wait for confirmation

This code creates a transaction, signs it with a private key, and sends it to the blockchain network.

Execution Table

Step	Action	Data/Variable	Result/Output
1	Create transaction data	tx = {"to": "0xABC123", "value": 10}	Transaction object ready
2	Sign transaction	signed_tx = sign(tx, private_key)	signed_tx contains signature
3	Broadcast transaction	broadcast(signed_tx)	Transaction sent to network
4	Network validation	signed_tx	Transaction is valid
5	Add to block	signed_tx	Transaction included in block
6	Confirm transaction	block confirmation	Transaction confirmed on blockchain

💡 Transaction confirmed, process complete

Variable Tracker

Variable	Start	After Step 1	After Step 2	After Step 3	After Step 4	After Step 5	Final
tx	undefined	{"to": "0xABC123", "value": 10}	{"to": "0xABC123", "value": 10}	{"to": "0xABC123", "value": 10}	{"to": "0xABC123", "value": 10}	{"to": "0xABC123", "value": 10}	{"to": "0xABC123", "value": 10}
signed_tx	undefined	undefined	signed transaction object	signed transaction object	signed transaction object	signed transaction object	signed transaction object
confirmation	false	false	false	false	false	true	true

Key Moments - 3 Insights

Why do we need to sign the transaction before sending it?

Signing proves the transaction is from the owner of the private key. See step 2 in the execution_table where signing creates signed_tx.

What happens if the network finds the transaction invalid?

The transaction will not be added to a block or confirmed. In the execution_table, step 4 shows validation; if invalid, the process stops there.

Why do we wait for confirmation after broadcasting?

Confirmation means the transaction is securely recorded on the blockchain. Step 6 shows confirmation after inclusion in a block.

Visual Quiz - 3 Questions

Look at the execution_table, what is the value of 'signed_tx' after step 2?

A A transaction object with a signature

B An unsigned transaction object

C The private key

D The transaction confirmation status

💡 Hint

Check the 'Data/Variable' column at step 2 in the execution_table.

At which step does the network check if the transaction is valid?

A Step 1

B Step 4

C Step 3

D Step 6

💡 Hint

Look at the 'Action' column for validation in the execution_table.

If the transaction is not confirmed, which variable in variable_tracker remains false?

A tx

B signed_tx

C confirmation

D private_key

💡 Hint

Check the 'confirmation' variable values in variable_tracker.

Concept Snapshot

Sending transactions:
1. Create transaction data (recipient, amount).
2. Sign with private key to prove ownership.
3. Broadcast to blockchain network.
4. Network validates transaction.
5. Transaction added to block and confirmed.

Full Transcript

Sending a transaction on a blockchain involves creating the transaction data with recipient and amount, signing it with your private key to prove ownership, then broadcasting it to the network. The network checks if the transaction is valid, and if so, includes it in a block. Once the block is confirmed, the transaction is confirmed on the blockchain.